The present invention broadly relates to improvements in cards or carding machines and pertains, more specifically, to a new and improved card or carding machine containing a spacing sensor arrangement. The present invention also relates to a new and improved method of checking the spacing between a main carding cylinder and carding-machine parts arranged opposite the latter.
Generally speaking, the card or carding machine of the present development is of the type comprising a main carding cylinder and parts adjustable relative thereto, such as a licker-in or licker-in cylinder, a stationary flat, a revolving flat and a doffing cylinder, such parts preferably having a nominal spacing relative to the main carding cylinder.
During assembly of a card or carding machine and during operation of such card or carding machine it is very important to accurately set and maintain the working or operational spacing between the spike clothing of the main carding cylinder and the corresponding clothings of the parts which cooperate or interact with the main carding cylinder.
These settings or adjustments have been hitherto manually effected by using gages. Such operation is relatively time-consuming and costly and can only be carried out by special skilled personnel. A further significant disadvantage lies in the fact that it was hitherto not possible to check the set or adjusted spacing during the actual operation of the card or carding machine. Therefore, it was extremely difficult to detect any changes in the settings or adjustments that were carried out, such changes resulting from centrifugal forces and thermal expansion.
In order to gain control of the problems in connection with thermal expansion, it is known, for example, from U.S. Pat. No. 4,499,632, granted Feb. 19, 1985 to maintain substantially constant and uniform the temperature of the main carding cylinder by means of a heat carrier. It is readily conceivable that such measures require a correspondingly high constructional expenditure and, moreover, are susceptible to leakage.
It is also known from German Patent No. 2,948,825, published Nov. 29, 1979 to maintain the working or operational conditions between two rotating cylinders of a staple fiber processing machine, which cylinders each are equipped with spiked clothing and process or mutually transfer a fiber web or fleece, by constantly adapting or surfaces to a predetermined value. For this purpose, there are provided positioning or adjusting devices which render possible a very accurate adjustment of the distance or spacing between the axes of rotation of the two rotating cylinders, the positioning or adjusting devices being controlled by means of control devices. The measurement signal of a parameter having a direct correlation to the diameter of one of the two rotating cylinders, such parameter being determined by a measuring unit, is supplied to the aforesaid control devices, whereby the latter then control the positioning or adjusting devices as a function of the aforementioned parameter. It is thus achieved that the disturbing influences of the centrifugal force and heating of the cylinders on the working or operational conditions are entirely precluded.
The aforesaid positioning or adjusting devices are either mechanical positioning means or thermally extensible structures, the length of which can be varied by the supply or removal of thermal energy.
The measurement signals which are supplied to the control means are, for example, the rotational speed of the main carding cylinder and/or the temperature thereof.
Furthermore, it is known that it could be possible to directly measure the spacing between the cylindrical surfaces or measure the diameter of the main carding cylinder by means of a corresponding suitable measuring unit, for example, a noncontact or contactless sensor or sensing device or a photo-optical measuring device.